Please report any and all bugs you find in Minecraft to bugs.mojang.com. If nobody reports a bug, we can't fix it!

To get snapshots, open your launcher and go to the "launch options" tab. Check the box saying "Enable snapshots" and save. To switch between the snapshot and normal version, you can find a new dropdow menu next to the "Play" button. Back up your world first or run the game on in a different folder (In the "launch options" page).

Snapshots can corrupt your world, please backup and/or run them in a different folder from your main worlds.